Kongsberg Simrad SU90 Operator's Manual page 178

Simrad SU90 Operator Manual
the visible defect may be a lot harder to see. In all cases, the echoes from the
neighbouring channels cause an interpolation that will restore a lot of the degraded
presentation.
Which actions to take if single channels fail depend on the operational impact, the
overall performance of the SU90 system, and a cost/benefit assessment. The most
important factor in the cost/benefit assessment is whether you need to replace the
transducer, or just a single transceiver board. If more than 3% of your transducer
elements have failed, we recommend that you contact your dealer for advice.
Note
For further investigations of this issue, use the functionality offered by the
(Element Built In Test Equipment) dialog box.
BITE
8 If the result from the reception test shows a number of transducer elements that are
either defective or offer reduced performance, repeat the test.
With the vessel in port, the environmental conditions are not satisfactory. In the
shallow waters of the port, noise from other vessels, dockyard workers or machinery
will cause unreliable test results. If you do this tests in a busy harbour, or with noise
sources present, the sensitive receivers will detect all the noise in the nearby waters.
Excessive noise or interference may be misinterpreted as physical defects.
You may need to repeat the test several times, and - if necessary - implement a
"silent ship" to improve the conditions.
9 Finish the test.
a Close the
BITE
b Set
Tx Power
c Hoist the transducer back up to its upper position.
Further requirements
If the noise level is higher than specified, you must check the reason(s) for this.
• Check the grounding of the Transceiver Unit.
• Verify that other electric equipment and/or machinery on board, such as cooling
systems, hydraulic pumps, electric motors etc, do not influence on the noise reading.
Switch off as much machinery as possible, especially electrical motors.
• Check for interference from other hydroacoustic systems.
• Check for environmental noise, such as other vessels in the vicinity or animal life.
Related topics
Testing the noise conditions and the sonar functionality, page 172
176
(Built In Test Equipment) dialog box.
to Off.
Element
381291/D